Wireless communication systems are widely deployed to provide various types of communication content such as voice, data, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., bandwidth and transmit power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, 3GPP Long Term Evolution (LTE) systems, and orthogonal frequency division multiple access (OFDMA) systems.
Generally, a wireless multiple-access communication system can simultaneously support communication for multiple user equipment devices (UE). Each UE communicates with one or more base stations, such as an evolved Node B (eNB) via transmissions on the forward and reverse links. The forward link (or downlink) refers to the communication link from the eNBs to the UEs, and the reverse link (or uplink) refers to the communication link from the UEs to the eNBs. This communication link may be established via a single-in-single-out, multiple-in-single-out or a multiple-in-multiple-out (MIMO) system. In this regard, the UEs can access wireless network via one or more eNBs.
Additionally, LTE radio access functionality has been extended into unlicensed frequency spectrums, such as the Unlicensed National Information Infrastructure (U-NII) band used by Wireless Local Area Network (WLAN) technologies. This extension of cell LTE operation is designed to increase spectral efficiency and hence capacity of the LTE system, and is often provided by small cells. Examples of technologies that provide LTE functionality over WLAN technologies include LTE in an unlicensed spectrum (LTE-U), which can utilize a 20 megahertz (MHz) channel bandwidth, 15 kilohertz (KHz) subcarrier spacing, and a 30.72 MHz sampling rate, and enhanced component carrier (eCC), which can utilize a 20, 40, or 80 MHz channel bandwidth, a 75 KHz subcarrier spacing, and a sampling rate proportional to 38.4 MHz (e.g., depending on the channel bandwidth). As these technologies utilize the unlicensed spectrum, wireless communications, including multicast communications, may be transmitted according to a communication schedule (e.g., a discontinuous receive (DRX) cycle) so as to minimize interfere with other devices using the spectrum. This may present challenges in multicast communications to devices that may not receive communications at the same time. In addition, in LTE or other cellular technologies, a DRX mode may be utilized by devices to conserve radio resources where the devices in DRX mode may periodically turn receiver resources on and off, which may similarly present challenges in multicast communications to devices having differing DRX cycle parameters.